We’ve got a Loquat tree that’s probably about 12 years old now, and maybe 10 feet tall. It has produced varying quantities of fruit the past few years. Some fruit is emerging this year, but probably not as much as we had 2-3 years ago. This disease or whatever it is has been apparent for a few years now. It started as a single ring circling around one of the lower limbs. Wonder if you have any idea what’s causing it and if we should be doing something to deal with the matter. Thanks much, Jerry B.

Dear Jerry,

I am thrilled to hear about your Loquat (Eriobotrya japonica e-ri-o-BOT-ri-ah ja-PON-i-ca) and the fact that you have had it growing for over ten years. I was first introduced to this wonderful small ornamental tree back in the 1970’s when we were trying to find new plants to use in residential gardens. Most of the time was spent in trying to get them to survive our winters back then so that we never really saw its full potential in the landscape. When I moved to Natchez, MS right out of college many gardens utilized this small tree and it made quite an impact with its tropical looking foliage and small orange fruits. It is wonderful to hear that Loquat can find a home here in north Alabama and be one of the choices we have in selecting small ornamental trees.

Loquat is a native of China that was introduced to the Mid-East region and then into Europe and finally the United States in the late 1800’s. It is a small tree growing fifteen to twenty feet tall with an equal spread and is known for its evergreen, tropical looking foliage of glossy green leaves measuring up to twelve inches long by six inches wide. The undersides of the leaves are very hairy (pubescent) and are quite soft to the touch. Flowers emerge in late summer to early fall as four to six inch long panicles, grayish-white in color that are quite fragrant. Each flower panicle will then produce a fruit cluster of four or five individual fruits, yellow-orange in color. Because the flowers emerge so late in the summer, fruits do not ripen until late winter to early spring. For this reason I believe we are at the mercy of our winter temperatures to see if we can have viable fruit each year.

Loquat is considered hardy in zones 8-10 meaning it can take temperatures down to 10 degrees F. As I mentioned earlier, we were trying to grow Loquat here back in the 1970’s when we routinely had temperatures dipping into the single digits and often even below 0 degrees F which definitely impacted the viability of the plants. Since the 1990’s, the norm has been to have much more moderate temperatures and this has helped us to have plants like Loquat growing in our landscapes today where it was next to impossible in years past.

Now, your particular problem has to do with fruit production and if there is anything wrong with your trees. Loquat is a member of the Rose family and as such is susceptible to many of the same problems that plague other fruit trees. You will find the usual problems associated with aphids, scale, leaf spot diseases and root rots (especially found in sites with poor drainage) that many other fruiting plants contract. Since Loquat is an evergreen and the fruits are formed in late winter, spraying with Dormant oil is doable but one must be careful in how it is implemented. I would only spray the trunk of the tree and leave the foliage and fruit alone. I would utilize a spray of NEEM oil beginning in late March to help with both insect and disease control throughout the year. Since we are growing this tree for the fruit, one has to be very careful in using only products that are labeled for fruits and I like to stick to organic controls whenever possible. These two oil sprays fit that bill so add them to your arsenal.

After looking at your pictures I believe the problem with your tree is that you have had an outbreak of the pest known as the bark-eating caterpillar (Indarbela quadrinotata) that begins as a moth that lays its eggs in the cracks and crevices of the tree and then when the larvae emerges it begins eating away at the bark of the tree. This opens the tree up to other insect infestations and wounds for diseases to enter. I would imagine that the eggs were laid in frost cracks developed in the bark two years ago when we had some lower temperatures and this allowed the bug to get established. I would spray the affected area with Dormant oil now and then follow up with a spray of Dipel or Thuricide in April and May. These two products contain the bacteria known as BT that is a biological control for pest in the Lepidoptera family (caterpillars) and is very safe to use. I would fertilize your trees with an organic, slow release product in April and make sure they are watered during periods of drought in the summer. Healthy, thriving plants are the best defense against pests of this nature so while we may not be able to help your fruit crop this year, we can set the stage for next year’s harvest.

I hope this helps and thanks for sharing your Loquat story.

Tips of the Week:

• When pruning tree branches, make clean cuts just outside the branch collar (swollen area just past the bark ridge) – applying pruning paint is not necessary

• When covering plants for freeze protection, be wary of clear plastic – it heats up quickly once the sun comes out – use opaque coverings

• On cold, rainy days enjoy the beautiful pictures in the garden catalogs that arrive in the mail and dream of spring – it is just around the corner